The NSIDC has the latest observations and information on the progression of the summer sea ice melt in the Arctic. From their latest summary (dated Aug 3):

Arctic sea ice extent averaged for July 2011 reached the lowest level for the month in the 1979 to 2011 satellite record, even though the pace of ice loss slowed substantially during the last two weeks of July. Shipping routes in the Arctic have less ice than usual for this time of year, and new data indicate that more of the Arctic’s store of its oldest ice disappeared.

Average ice extent for July 2011 was 7.92 million square kilometers (3.06 million square miles). This is 210,000 square kilometers (81,000 square miles) below the previous record low for the month, set in July 2007, and 2.18 million square kilometers (842,000 square miles) below the average for 1979 to 2000.

On July 31, 2011 Arctic sea ice extent was 6.79 million square kilometers (2.62 million square miles). This was slightly higher than the previous record low for the same day of the year, set in 2007. Sea ice coverage remained below normal everywhere except the East Greenland Sea.

The latest sea ice extent image shows that since about Jul 20 that the sea ice extent is slightly greater than that for the same period in 2007, reflecting a slow down in the rate of sea ice extent loss.

The SEARCH Sea Ice Outlook is an international effort to provide a community-wide summary of the expected September arctic sea ice minimum. Monthly reports released throughout the summer synthesize community estimates of the current state and expected minimum of sea ice—at both a pan-arctic and regional scale. The intent of the SEARCH Sea Ice Outlook effort is not to issue predictions, but rather to summarize all available data and observations to provide the scientific community, stakeholders, and the public the best available information on the evolution of arctic sea ice.

The latest outlook was released on Jul 13, using end of June sea ice info:

We received 16 responses for the Pan-Arctic report (Figure 1), with estimates in the range of 4.0 to 5.5 million square kilometers for the September arctic mean sea ice extent. The median value was 4.6 million square kilometers; the quartile values were 4.3 and 4.7 million square kilometers, a rather narrow range given the intrinsic uncertainty of the estimates on the order of 0.5 million square kilometers. It is important to note for context that all 2011 estimates are well below the 1979–2007 September climatological mean of 6.7 million square kilometers.

There continues to be a consensus for continuation of an anomalously low sea ice extent similar to the values for 2008-2010 and below all previous values before 2007. The data show a continuing low value of sea ice extent at the beginning of the summer season and an appearance of a weather pattern (the Arctic Dipole) that tends to favor summer sea ice loss, in contrast to weak and variable summer winds of previous decades. Ocean changes may also be involved. According to the National Snow and Ice Data Center (NSIDC), arctic sea ice extent for June 2011 was the second lowest in the satellite data record since 1979. These new factors over the last several years seem to be holding the September sea ice extent at persistent low values below 5.0 million square kilometers.

I assume that we will see another round of forecasts (based on Jul data) within a week or so.

So why does the minimum sea ice extent matter? Well the state of the sea ice matters to people who live in the region, resource extraction activities, and general transportation issues (see the Arctic Imperative section below). In the context of the climate change debate, the Arctic is regarded as a bellwether for global climate change, and there is general interest in climate related records and their possible attribution to AGW.

In my previous post on this topic, I discussed the recent record of sea ice extent variability that is illustrated in this Figure.

While these data are most often interpreted in the context of a linear trend, it is instructive to interpret the record in the context of a (qualitative) change point analysis, defined by changes in trend, mean value, amplitude of the annual cycle, and interannual variability.

1979-1988: little trend, consistent interannual variability in the amplitude of the annual cycle.

1989-1996: small negative trend (more prominent in the summertime minima), large interannual variability.

1997- 2003: lower values relative to the period prior to 1996, with the most noticeable decrease in ice extent being the wintertime maximum; small amplitude and fairly regular annual cycle.

2003-2007: marked decrease in wintertime maxima; strong negative trend in both winter max and summer min; continued small amplitude of the annual cycle. A steady decline in wintertime maxima from 2003 to 2007 seems to have led the decline in summertime minima, with a marked decline beginning in 2005 that culminated in the major anomaly of summer 2007.

2007-present: return to a large amplitude annual cycle (with an increase in the wintertime max), but with a an overall shift to lower summertime values. The winter 2011 values look anomalously low, possibly with a pattern resembling 2006.

My previous post discusses the apparent impact of teleconnection regimes such as the AMO, NAO and PDO on the interannual variability and trends.

Of relevance to how the actual September minimum will play out, we need to understand the impact of weather variability on shorter subseasonal timescales to understand how the details of the ice freeze up will play out. A big storm in early Aug could further break up the existing ice: decreasing the ice concentration) but increase the ice extent. An early snowfall on existing ice could help speed up the freezing of melt ponds on the existing ice. Once September arrives, a high pressure system with few clouds could speed up the autumnal freezing. A heavy snowfall in autumn could drastically reduce the winter ice growth. Etc. We shall see how this all plays out.

On thin ice?

Sea ice extent is only part of the sea ice story: ice thickness is a critical indicator of the state of the sea ice. The European Space Agency (June 21) reports on the first ice thickness map of the Arctic from its new CryoSat2 satellite.

The first map of sea-ice thickness from ESA’s CryoSat mission was revealed today at the Paris Air and Space Show. This new information is set to change our understanding of the complex relationship between ice and climate.

From an altitude of just over 700 km and reaching unprecedented latitudes of 88º, CryoSat has spent the last seven months delivering precise measurements to study changes in the thickness of Earth’s ice.

CryoSat measures the height of the sea ice above the water line, known as the freeboard, to calculate the thickness. The measurements used to generate this first map of the Arctic were from January and February 2011, as the ice approaches its annual maximum.

The data are exceptionally detailed and considerably better than the mission’s specification. They even show lineations in the central Arctic that reflect the ice’s response to wind stress.

“It has taken about ten years to convert the initial proposal into a flying mission: ten years of hard work and dedication from a core team of less than a hundred people, ably assisted with crucial expertise from a few hundred more.”

ESA’s CryoSat Mission Manager, Tommaso Parrinello, added, “These first results are very exciting as we begin to see the mission’s potential realised.

“The coming months will be dedicated to completing the picture to gain better insight into how polar ice is changing.”

This is exciting news. Determination of sea ice thickness from satellite is not straightforward, so research on on the methodology is ongoing. Some previous efforts at satellite-derived sea ice thickness were made using NASA’s IceSat.

Sea ice variations in the late Holocene

From Copenhagen, news of a new paper to be published in Science on sea ice variations over the last 10,000 years. Quotes from the lead author Svend Funder:

“Our studies show that there have been large fluctuations in the amount of summer sea ice during the last 10,000 years. During the so-called Holocene Climate Optimum, from approximately 8000 to 5000 years ago, when the temperatures were somewhat warmer than today, there was significantly less sea ice in the Arctic Ocean, probably less than 50% of the summer 2007 coverage, which is absolutely lowest on record. Our studies also show that when the ice disappears in one area, it may accumulate in another. We have discovered this by comparing our results with observations from northern Canada. While the amount of sea ice decreased in northern Greenland, it increased in Canada. This is probably due to changes in the prevailing wind systems. This factor has not been sufficiently taken into account when forecasting the imminent disappearance of sea ice in the Arctic Ocean.”

“Our key to the mystery of the extent of sea ice during earlier epochs lies in the driftwood we found along the coast. One might think that it had floated across sea, but such a journey takes several years, and driftwood would not be able to stay afloat for that long. The driftwood is from the outset embedded in sea ice, and reaches the north Greenland coast along with it. The amount of driftwood therefore indicates how much multiyear sea ice there was in the ocean back then. And this is precisely the type of ice that is in danger of disappearing today,” Funder says.

“Our studies show that there are great natural variations in the amount of Arctic sea ice. The bad news is that there is a clear connection between temperature and the amount of sea ice. And there is no doubt that continued global warming will lead to a reduction in the amount of summer sea ice in the Arctic Ocean. The good news is that even with a reduction to less than 50% of the current amount of sea ice the ice will not reach a point of no return: a level where the ice no longer can regenerate itself even if the climate was to return to cooler temperatures. Finally, our studies show that the changes to a large degree are caused by the effect that temperature has on the prevailing wind systems. This has not been sufficiently taken into account when forecasting the imminent disappearance of the ice, as often portrayed in the media,” Funder says.

This is a very interesting and important paper. I have long been frustrated by the lack of a good paleo record of sea ice extent over the past several thousand years. The reason is that the signature of sea ice is not obvious or unambiguous in the various paleo proxy records. The driftwood on the coast of Greenland is an interesting proxy for sea ice extent.

Amount and timing of permafrost carbon release in response to climate warming

K. Schaefer, T. Zhang, L Bruhwiler, A. Barrett

Abstract. The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO2 concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate. We use surface weather from three global climate models based on the moderate warming, A1B Intergovernmental Panel on Climate Change emissions scenario and the SiBCASA land surface model to estimate the strength and timing of the PCF and associated uncertainty. By 2200, we predict a 29–59% decrease in permafrost area and a 53–97 cm increase in active layer thickness. By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 ± 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42–88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

Well, permafrost and its feedback with climate change is a known unknown, and after this paper, I would say it is still a known unknown. I’m not dismissing the paper at all (I haven’t read it), plus permafrost thawing is one of the genuine possible tipping points associated with AGW. But given the assumptions in the paper apparent from the abstract, I don’t see anything here to justify Romm’s alarm.

Moderation note: This is a technical thread that will be moderated for relevance. A companion thread “Arctic Imperative” (forthcoming tonite) will provide a forum for discussion of socioeconomic, policy, and political issues in the Arctic.

I’m not sure either, but OHC hasn’t increased despite the open water up there.

Water does give out a large amount of heat when it freezes, and since there’s been a heavily negative Arctic Oscillation the last couple of winters it would have frozen under cloudless skies – sending a great deal of that heat out into space.

I’m not confident that climatologists would investigate such a thing. Rocking the boat and such.

“afer this paper, it’s still a know unknown”
what a curious and hypocritical way to dismiss a paper… well of course it hasn’t fully solved the issue, I’m sure. Like a new paper on climate sensitivity or sea level rise doesn’t fully solve all uncertainties. Like allmost every new paper on any vast subject, actually. And as a modelling work with projections for the future it necessary remains uncertain (I haven’t read the paper… and neither have you apparently – but that desn’t prevent you from dismissing it…). But that doesn’t make it irrelevant or uninteresting, or no cause for concern.

The record, Antarctic Ice Core Data, supports your conclusion. The earth did not experience massive release of methane in the last 400,000 years, even though the earth went through stronger warming cycles than the present warming trend. Therefore, there is no reason why the earth would release massive amounts of methane now.

It is also worth pointing out that given this pattern the use of words like normal and average is highly misleading. Those words in ordinary use derive their meaning from an underlying normal distribution, which we clearly do not have. There is no normal value in this pattern, and the arithmetic average has no physical meaning.

The term longterm warming is a semantic trick. It refers to the fact that the 2000’s are warmer than the 1990’s, etc. If you have a lag model that explains how warming precedes melting by a decade or so, bring it on. Otherwise my point stands. Temps did not increase globally over the period when ice decreased so global temps increasing cannot be the simple explanation.

lolwot & rust, you are not responding to what I said, just blowing smoke. Correlation is not causation but it is usually a necessary condition for causation. There is no correlation between the ice pattern and global temperatures, over the entire period of record. Nor to the pattern for arctic warming, or even regional warming within the Arctic, for that matter, if memory serves.

Science is about specifics. Perihelion of Mercury, Michelson-Morley, little stuff like that. You can’t just say oh there is warming (vaguely) and there is melting (vaguely) so the warming must be causing the melting. That is not science. (It is however frequently heard which is the real problem.)

Dear David:
You are right! A correlation between ice melting and surface temperature warming does not exist. In fact, present surface temperature rise is in the order of 0.0000002 degrees centigrade per hour, and based on heat transfer equations available to us, every model will give insignificant amount of ice melting due to surface temperature rise. Because this infinitesimal temperature rise is too small to induce convective or conductive heat transfer large enough to melt ice. Ice can only melt by the availability of water vapor whose condensation melts ice. For proof, please see Article-9, Experiment-glaciers lymelt by water vapor condensation, posted on my website:www.global-heat.net

You don’t need constantly increasing temperatures to melt ice. You just need temperatures to rise above a level that would allow stability in its present state. If you take an ice cube out of the freezer and put it on the kitchen bench it will eventually melt even with the room staying at the same temperature.

For a long term example I believe 6 deg C warming is thought to be enough to melt both the Greenland and Antarctic ice sheets but that could take several thousand years to play out, even if 6 deg C is reached within the next 100-150 years.

david. temperatures do not have to increase globally to have an impact on ice. They have to increase regionally: Like so:

You seem to be confused by what the global average is and what it is not. It is not a measure of a physical thing. It’s an index, a proxy that merely gives you an idea of how the ‘average’ location warmed.

TB: I hope you are correct, but it could be a blow out of monumental proportions. “baby” ice is gunna get tested over the next 10 days. huge blow out is possible.. Lucia says its 20% chance we beat the min. The climate has beat up the ice, lets see if the weather delivers the death blow.

Excellent point!
The terms of Normal and Mean are extremely misleading and are prone to cherry picking.
Choose the beginning and the end of a time line and you will get your desired numbers and trends.

That graph is of sea ice area, which is different than sea ice extent.

And anyway, if that graph gets to twice as large a negative anomoly at the september minimum as it is now, then the sea ice is gone.

Which would be complete melting.

My initial comment was referring to this comment in the post

“The latest sea ice extent image shows that since about Jul 20 that the sea ice extent is slightly greater than that for the same period in 2007, reflecting a slow down in the rate of sea ice extent loss.”

“The bad news is that there is a clear connection between temperature and the amount of sea ice. And there is no doubt that continued global warming will lead to a reduction in the amount of summer sea ice in the Arctic Ocean.”

This sentence needs at least one edit. Because most people will read “global warming” as CAGW, the word ‘global’ should be eliminated from that phrase. After all, the thesis is about the effects of warming on the sea ice, not about the effects of something definitely known to be global warming.

So sorry you don’t know what global warming is. It comes down to education. You just need to hit the books. You should learn what the words mean before you embarrass yourself and other members of your faith by spouting this nonsense.

You are obviously a very wise and unbelievably clever person , so please take some of your valuable time-which no doubt is being mostly used to bring home a well deserved Nobel prize- to educate me and tell me how regional warming becomes ‘global’ warming.

Are you saying there are no cooling trends of a statistically meaningful (30 years) nature that are ocurring on our globe?
tonyb

Sorry, it’ll be more meaningful to you if you figure it out for yourself. Like all the best teachers, I’m not here to do the work for you, merely to encourage you on your own journey of discovery. I’ve pointed you in the direction of the right answer. Let me know how you get on.

Now, back to the Arctic. The Arctic warming is relevant not just as a marker of global warming, but as a cause of several different positive feedbacks contributing to global warming, including the changes in albedo, melting of permafrost, decomposition of methyl hydrate deposits, and increased burning of boreal forests and peat. The degree to which each of the feedbacks will impact the rate of global warming in the next century is cannot be estimated with great confidence, but that does not mean we can assume the contribution to be negligible.

‘A final clue emerged. Analyzing satellite and in-situ ocean data, the researchers said a large amount of pack ice and fresh water was exported into the northwest Labrador Sea in the summer of 2007. This froze the following winter, significantly extending the ice edge farther offshore. As a consequence, cold air from the North American continent traveled farther over ice, instead of warmer ocean waters, remaining cold until it hit warmer open water in the middle of Labrador Sea. The resulting temperature contrast helped trigger the sinking process.’

This is from the Woods Hole Oceanographic Institute abrupt change page. This is a negative feedback. Abrupt change itself is a topic that is little appreciated. Climate changes abruptly because there are multiple interacting negative and postive feedbacks and uncertain thresholds.

With various modes of low frequency variability – as I disccused above – I find it difficult to imagine that even the direction of Arctic temperature is by any means certain. Low frequency modulation of the NAO by solar interactions with ozone in the stratosphere is tentatively linked to the temperature variability – there is a reference above.

May I remind everyone that truth in dialectic is achieved through civility, honesty, good faith, humor, humility and tolerance. There is room for robust discussion – but when this descends into petty snarking it is unpleasant and counterproductive. Just do a final check and think – do I really need to say? If the answer is yes in the sense of a Socratic challenge – go right ahead. Mostly it isn’t and it is better to maintain humor and dignity.

People should keep an open mind and remember that no one has more than an inkling of the multitude of factors in the immense complexity of the Earth’s climate system.

Most of the current pestiness, incivility and demeanour springs due to deep frustration to the inability to change people’s minds to what is to one so “obvious”. This frustration deepens when you really believe that your own fate is intertwined and dependent to these people’s (apparently insane) beliefs.

Imagine yourself in a conceptual situation, where you are trapped inside a train that is going high speed. A group of people find out that this rail is going towards a precipice. They gather evidence for it, and although it is not unequivocal, it’s not bad evidence at all. Then they go speak to the others and they just don’t buy it. Now if you believe all this stuff, you will get frustrated and angry. You’ll become paranoid: “this denial has a purpose, someone’s behind this evil, this is a movement with an agenda”. You will call these people as “useful idiots”, you’ll be dazzled at their “stupidity”.

Global refers to the extent of the averaging. It is NOT a description of the uniformity of the effect. If we thought the effects were UNIFORM then there would be no push for regional forecasts.

The warming we expect will not be uniform. It wil not be monotonic. The changes in precipitation will not be uniform or monotonic. the changes in sea level will not be uniform or monotonic. Climate is not simple.

What the word “global” refers to is the spatial domain over which averages are calculated. If we posit a 1C average global warming, rest assured we know that some places will see less than that. They have to because the spatial distribution of warming is not homogenous. If the equator warms by 1 degree then plor amplification would suggest a 4C warming at the pole. The warming isnt homogenous, nobody ever said it would be and discovering that it’s not is no surprise.

Global refers to the extent of the averaging. It is NOT a description of the uniformity of the effect. If we thought the effects were UNIFORM then there would be no push for regional forecasts.

The warming we expect will not be uniform. It wil not be monotonic. The changes in precipitation will not be uniform or monotonic. the changes in sea level will not be uniform or monotonic. Climate is not simple.

What the word “global” refers to is the spatial domain over which averages are calculated. If we posit a 1C average global warming, rest assured we know that some places will see less than that. They have to because the spatial distribution of warming is not homogenous. If the equator warms by 1 degree then plor amplification would suggest a 4C warming at the pole. The warming isnt homogenous, nobody ever said it would be and discovering that it’s not is no surprise.

What happened in the 1990s was that the former USSR went out of business. What happened in the 2000s was that the gas was worth enough money to fix the leaks in the sundry pipelines and tighten up the wells. Fracking may make more leaks, that is one of the problems (there was a recent push everything one way paper on this, but it is a serious issue, and even in the US the pipelines leak a lot)

What happened in 2007 was that the IPCC took two decades of methane rise and extrapolated it out forever. Stupid move. Makes them look foolish to anyone with a brain and kicks another wheel off of the fail-train of catastrophic warming.

Looks like we’ll get a fifth of their projection – for whatever reason.

Eli I am in the Oil and Gas Business and yes the USSR went out of business, but their production did not. It is doing just fine thank you. The price in the 2000’s was unremarkable and no where near a high for the last 40 years. And excuse me, but you obviously know nothing about fracturing. It is astounding how much misinformation is out there about this process. There are lots of things to complain about in the oil industry. Why people seem to ignore so much, to focus on so little is astounding to me. It makes me wonder when I see how excited and adamant people can become, who have so little knowledge about what they fear. But then any good Social Psychologist will tell you that where there is the least structure, you have the largest canvas to project your own emotions.

Mostly in the years 1990-1995. You can also see it (if you look hard) in the CO2 record. As a marker Russian oil output fell from ~480 million tons per year in 1989 to about 300 in 1995 and stayed flat until ~2000

Se the graph on page 52 at fpc.org.uk/fsblob/307.pdf

In addition, the opening of major pipelines to the west in the late 1990 early 2000s probably caused the Russians to tighten up on leaks

A nice handwavey idea, but possibly less definitive than
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0404412101)
which is an explanation of methane uptick caused by reduced suppression by acid rain. Google acid rain and methane for several relevant articles in the first few hits.

When people panic about the sea ice beng lower than… well, since records began, I recall Kipling’s little poem:

In April was the jackal born,
The rains fell in September.
‘Now such a fearful flood as this’,
said he ‘I can’t remember.’

“It (the rate of change of something, the concentration of something, the rate of warming compared to something to which it is not comparable, like the temperature difference between day and night, etc) seems small to me and therefore it’s insignificant” is not a very sound chain of reasoning.

Especially since the IPCC is expecting about 500 ppb rise in the next 40 years. Another busted projection.

What part of “In the next forty years” is confusing to you? Or is there a new axiom of denier logic at work here? We should start a list:

1. Things that are, like, small, can’t possibly be important.
2. Things that start at a given rate cannot accelerate; therefore any projection of what may happen in the future can be falsified right now based on the current trend.

“try learning not to patronise.”

People (like you) that say idiotic things are going to feel stupid when their noses are rubbed in the facts. That’s not under my control. Don’t act dumb(*), and you won’t have to feel dumb when somebody blows a gaping hole in your story.

* Remember that a time-honored method of not acting dumb is to keep your mouth shut until you know what you are talking about.

It tickles me the way deniers who lost the argument over “AGW” have had to invent “CAGW” in order to continue the argument. Every time you tack “catastrophic” in front of “climate change” or AGW, you are admitting you were wrong to deny climate change and that that denial is no longer tenable — you have to invent a new, pretend theory to be in opposition to.

People (like me, a landslide majority of the population of the planet) think – rightly or wrongly – that climatologists are carpetbagging liars.

Deniers like you are about ten percent of the population in the US, and falling (less in the rest of the world). 76% of the public in the US reports trusting scientists — scientists have the highest trust of any source in the poll (1). So the whole “common man is on my side” delusion is just another lie from a serial liar.

Halpern and Grant Foster are old enough to know what a denier is so they know how they have unscrupulously perverted that awful word.

You’re not old enough to know what that words means Robert.

It still has the same meaning despite charlatan scientists’ and their cronies’ attempts to denigrate the suffering and memories of the victims of the Holocaust. But it’s for a good cause, right?

Ipsos MORI conducted a poll of 18,000 people in 24 countries in February. They gave those questioned a list of 15 environmental problems and asked to pick the 3 most pressing ones for them and their representatives to address. Remember, the could pick three out of 15.

We lost the CAGW battle in BC a couple of years back and CO2 taxes certainly halted global warming here. Record winter snowfall and no summer to talk until a week ago. Local corn less than 2 feet tall in the fields. Plants all a month or more late in blooming. Our tax money hard at work preventing global warming.

Interannual changes of Arctic sea ice are related to varying storm activity
Fewer summer storms favor low sea ice at the end of the melt season
Storms impact the cloud cover and ice motion, and consequently sea ice melt

James A. Screen et al

The perennial (September) Arctic sea ice cover exhibits large interannual variability, with changes of over a million square kilometers from one year to the next. Here we explore the role of changes in Arctic cyclone activity, and related factors, in driving these pronounced year-to-year changes in perennial sea ice cover. Strong relationships are revealed between the September sea ice changes and the number of cyclones in the preceding late spring and early summer. In particular, fewer cyclones over the central Arctic Ocean during the months of May, June, and July appear to favor a low sea ice area at the end of the melt season. Years with large losses of sea ice are characterized by abnormal cyclone distributions and tracks: they lack the normal maximum in cyclone activity over the central Arctic Ocean, and cyclones that track from Eurasia into the central Arctic are largely absent. Fewer storms are associated with above-average mean sea level pressure, strengthened anticyclonic winds, an intensification of the transpolar drift stream, and reduced cloud cover, all of which favor ice melt. It is also shown that a strengthening of the central Arctic cyclone maximum helps preserve the ice cover, although the association is weaker than that between low cyclone activity and reduced sea ice. The results suggest that changes in cyclone occurrence during late spring and early summer have preconditioning effects on the sea ice cover and exert a strong influence on the amount of sea ice that survives the melt season.

I think the article by James screen et al is very important. As a school child I was taught Britains weather was characterised by ‘war, wet westerly winds.’

On moving to the west coast of Britain I realise that Easterlies are also very dominant in certain years. Looking back through one of Lambs books there is a good chart that shows the westerlies disappeared at times during the LIA.

The easterlies have a profound effect on our local beach-it destroys it-the westerlies have no effect whatsoever. Simailarly sand dunes are notably affected by different wind directions.

I think you need look no further than the effects of winds/tides/storms as being some of the major causes of initial ice break up (which doesn’t mean there aren’t others)

Here we explore the role of changes in Arctic cyclone activity, and related factors, in driving these pronounced year-to-year changes in perennial sea ice cover. Strong relationships are revealed between the September sea ice changes and the number of cyclones in the preceding late spring and early summer… Fewer storms are associated with above-average mean sea level *pressure*, strengthened anticyclonic winds, an intensification of the transpolar drift stream, and reduced cloud cover, all of which favor ice melt.

You know what else corresponds to higher pressure? Higher temperature!

PV=nRT

So, higher temperatures cause ice to melt, and they also happen to cause a change in the *pattern* of Arctic cyclones, a plausible effect of variations in heat. The latter is an interesting finding to pin down, sure, but ice still melts due to its temperature, that is Settled Science, and your argument to the contrary is blatantly unphysical.

The correlation of temperature to cyclone patterns does not make the cyclone patterns the *driver* of anything.

“Here we explore the role of changes in Arctic cyclone activity, and related factors, in driving these pronounced year-to-year changes in perennial sea ice cover. Strong relationships are revealed …”

Strong relationships are only correlation. You have *assumed* causation, falsely, on flagrantly unphysical reasoning.

The results suggest that changes in cyclone occurrence during late spring and early summer have preconditioning effects on the sea ice cover and exert a strong influence on the amount of sea ice that survives the melt season.

What “preconditioning effects?” Occam says you should first examine the possibility, highly likely due to existing, very robust theory, that both storm patterns and amounts of melting ice are direct results of the temperature itself. Neglecting to rule out that obvious likelihood before making up unphysical “preconditioning effects” reveals deep, unscientific bias.

Interestingly, this study and other attempts to model permafrost dynamics have the same problem the ice sheet modeling does: they don’t have an good way to account for the powerful heat-transferring effects of liquid water.

can we all scientifically agree that any daily or monthly thaw-by-thaw analysis of Arctic sea ice is wholly antiscientific in the context of climate, and even yearly and decadal stuff is dubious to say the least, simply because as David W just said, we know nothing about normal “average”, let alone normal “variance”? otherwise we might as well be monarch butterflies worried it’s warmer when we die in the summer than when we were born in the spring.

Well we do want to figure out how to predict sea ice extent on seasonal, interannual and decadal time scales, because there are substantial economic implications (my next post will address some of these issues). so watching the sea ice closely and trying to figure out how to make seasonal predictions of sea ice extent is the first step. As a climate change bellwether, i think the exercise is less useful

Dr. Curry,
Why do you think the sea ice is predictable over decadal time scales?
I look forward to the economic impacts of variations in Arctic sea ice. Will you also cover the implications of greatly expanded sea ice extent?

Really Steve? Isn’t it part of the spatiotemporally chaotic climate system, and as a small portion of it (with a high sensitivity apparently, though I am corrupting the term), wouldn’t it be subject to even less predictable fluctuations than the global climate?

“Though only about 1% of global ocean volume, the Arctic Ocean receives almost 10% of global river discharge. As a consequence, organic carbon transported by arctic rivers has the potential to strongly impact the chemistry and biology of the Arctic Ocean.”
[www.sciencedaily.com/releases/ 2008/02/080212134803.htm]

Wagathon’s figures mean that the Arctic Ocean receives 10x as much river discharge per volume of ocean water, so the real question to ask is, do Arctic rivers contain more or less than 1/10th the dissolved organic carbon (DOC) of other rivers? Anything more than 1/10th means the Arctic Ocean’s chemistry and biology are indeed more strongly impacted by river discharge. While it’s quite plausible to me that warmer rivers have more DOC, I wouldn’t just assume that the difference is a factor of 10 or more, and so I’m not blowing off what Wagathon linked, this time, just yet.

Syun-Ichi Akasofu — “Young researchers are interested in satellite data, which became available after 1975. All the papers since [modern satellite imaging] show warming. That’s what I call ‘instant climatology.’ I’m trying to tell young scientists, ‘You can’t study climatology unless you look at a much longer time period.'”

It isn’t clear at all if this report represents a change in TOA energy flow balance or if it represents a redistribution of energy already here and sequestered. Redistribution of heat already here is not global warming even if the result is to melt the entire Arctic ice cap.

Just checked out your link. I’m certainly not paying $60 for a book originally published in 1968. I think I’ll stick to Lamb who conducted a lifetimes pratical study of the climate and whose books already reside in my personal library together with many others.

Can I suggest you read some of his stuff-it might cure your warmism :)

1) Are global climate models generally correct in that anthropogenic Greenhouse gases, with CO2 being the chief one, adding to the current decline in arctic sea ice beyond any natural variability and will we likely see a seasonally ice free arctic this century?

2) Are there likely “black swan” events or tipping points, such as the melting of permafrost that will dramatically hasten the pace of arctic climate change?

3) Rather than look to periods such as the Holocene climate optimum for comparisons to modern sea ice extents, in which Milankovitch NH insolation was a bit greater, does it make more sense to look to a period in earth’s history when Milankovitch forcing was about the same as today and CO2 levels were also at the higher levels we see today- i.e. should we be looking at points in the Pliocene period for a more accurate comparison of where we might be headed, as studies like this one have done:

I will qualify this to say that temperature won’t reach Cretaceous levels until Greenland and Antarctica have melted which is bit longer term, but the Cretaceous CO2 levels did not permit stable polar ice whether continental or sea-ice.

Actually there is strong evidence that there were major icecaps (on the order of 10^7 km^3) in Antarctica during at least part of the Cretaceous. The repeated abrupt sea-level changes (tens of meters in <1 Ma with parallell d18O shifts) can only be explained by glacial withdrawal of water from the oceans.
Whether Antarctica was completely ice-free in between these cooler intervals is unknown since sea level/d18O can only record changes in ice-volume not absolute levels.
It should be noted that IRD (Ice-rafted debris) which is usually used as a signal for glaciation requires major tidewater glaciers which usually requires quite large icecaps. Iceland for example, which is fairly heavily glaciated, still does not have a single glacier that reaches the coast and therefore produces no IRD..

As for the effect of warming on permafrost it is interesting to see what happened during the previous interglacial (MIS 5e) about 117-127 Ka BP. This was markedly warmer than the present one, particularly in the Arctic and in Siberia most of all. In this area which is the major area of permafrost on the planet both summer and winter temparatures were up to 10 degrees C warmer than at present, and forest extended all the way to the Arctic coast.
Despite this warming lasting for at least several thousand years, the permafrost did not melt completely (since there is still premafrost older than MIS 5e around), and the considerable melting that did take place apparently had no dramatic effect on CO2 or CH4 levels in the atmosphere, to judge from ice-core measurements.

it is interesting to see what happened during the previous interglacial (MIS 5e) about 117-127 Ka BP. This was markedly warmer than the present one, particularly in the Arctic and in Siberia most of all. In this area which is the major area of permafrost on the planet both summer and winter temparatures were up to 10 degrees C warmer than at present,

TTY – Do you have a reference for that? I don’t recall MIS5e specifically, but the evidence for the last interglacial in general is conflicting, with some studies suggesting temperatures averaging only 1 or a few degrees C higher than today, and with sea levels perhaps several meters higher. The sea level rises have been interpreted to suggest that much of the difference from today came from Greenland and Antarctic ice melting, with much less due to thermal expansion of sea water.

There are several extremely doubtful assumptions made in that particular study. For one thing using Gaussian smoothing (3,000 years in a 10,000 year long interglacial!) on a sediment core is very questionable, since it is already smoothed by bioturbation. However I can understand doing it, since the unsmoothed curves are obviously impossible.
Secondly the method is critically dependent on the depth and profile of the Bab el Mandeb having remained constant since the Middle Pleistocene, which is highly unlikely since the Red Sea area is very tectonically active (as is indeed indicated by the reported MIS 5e shoreline levels from the Red Sea area in the supplementary information).
Third they assume that net evaporation was the same in MIS 5e as today, which is also highly unlikely since MIS 5e climate is known to have been much wetter than at present all around the Red Sea (e. g. Bir Tarfawi, Sodmein Cave, Negev, Rub-al-Khali) with permanent lakes and considerable vegetation in currently hyperarid areas.

Unfortunately there does not exist any good modern global reviews of last interglacial climate or sea level, but there is strong evidence that the climate was significantly warmer than at present and that sea-levels were not as high as usually claimed.
Much of the evidence for the “6 to 9 meter higher sea-level” that is usually cited comes from tectonically unstable areas or sites that were isostatically affected by MIS 2 and/or MIS 6 glaciation. Here is a good review for Australia, which is arguably the most tectonically stable part of the World:

And as for temparatures being only one or a few degrees warmer than, now. Would that really be enough for hippopotami to be able to live in Yorkshire? Or Water Buffaloes on the Rhine or Macaque monkeys in Bavaria for that matter.

And as for temparatures being only one or a few degrees warmer than, now. Would that really be enough for hippopotami to be able to live in Yorkshire? Or Water Buffaloes on the Rhine or Macaque monkeys in Bavaria for that matter.

I would say yes, for a 2 C difference in global mean temperature averaged over ten thousand years, with peaks and dips as well as regional variations..

I suggest that you take your posts that I judge off topic to the more open threads or older less active technical threads. this blog will become complete chaos if some control isn’t exercised on the active technical threads.

Sea ice variations in the late Holocene
This is excellent and timely information. In the past ten thousand years, it has been warmer than now and there has been less Arctic Sea Ice Extent than now. Each time, after it got warmer, it snowed and got cooler. This will happen now. This is happening now. The Sea Ice Extent is low and the snows have started. Cooler follows Warmer. Warmer follows Cooler. This is powerful negative feedback.
We need the warmer periods to provide the snow that replenishes the Glaciers. It doesn’t snow much when Earth is cooler. We need the warm periods to get the Snow we need to balance the temperature.
This would be a good time to expose people to Ewing and Donn Theory.
I wrote this without reading the responses. I will see if anything gives me second thoughts after I post this.

‘Understanding Arctic temperature variability is essential for assessing possible future melting of the Greenland ice sheet, Arctic sea ice and Arctic permafrost. Temperature trend reversals in 1940 and 1970 separate two Arctic warming periods (1910–1940 and 1970–2008) by a significant 1940– 1970 cooling period. Analyzing temperature records of the Arctic meteorological stations we find that (a) the Arctic amplification (ratio of the Arctic to global temperature trends) is not a constant but varies in time on a multi-decadal time scale, (b) the Arctic warming from 1910 – 1940 proceeded at a significantly faster rate than the current 1970 – 2008 warming, and (c) the Arctic temperature changes are highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting the Atlantic Ocean thermohaline circulation is linked to the Arctic temperature variability on
a multi-decadal time scale.’

‘We use the eight stations (Figure 1) with a virtually complete temperature record since the early 1880s to reconstruct the temperature history of the low Arctic, which is shown together with the mean global surface air temperature for 1880 –2008 in Figures 2a and 2b. There are three distinct periods in the lower Arctic temperature record: strong warming over 1880– 1940 and 1970 – 2008 separated by equally strong cooling from 1940 – 1970. The sudden changes in the Arctic temperature trends around 1940 and 1970 suggest that other factors besides slowly varying concentrations of greenhouse gases and aerosols, or solar changes, could have played a significant role.’

‘Based on these observational data, Polyakov et al. (2003) concluded that the “examination of records of fast ice thickness and ice extent from four Arctic marginal seas (Kara, Laptev, East Siberian, and Chukchi) indicates that long-term trends are small and generally statistically insignificant, while trends for shorter records are not indicative of the long-term tendencies due to strong low-frequency variability in these time series, which places a strong limitation on our ability to resolve long-term trends”. “Correlation analysis shows that dynamical forcing (wind or surface currents) is at least of the same order of importance as thermodynamical forcing for the ice extent variability in the Laptev, East Siberian, and Chukchi Seas ”’

The Arctic has pronounced multi-decadal temperature variability with temperature peaks in in the late 1930’s at temps similar to today’s . The strong cooling after 1940 – the Arctic amplification – is evidence that sulphate is not a primary factor in global multi-decadal variability.

So what drives this decadal variability? Recent work is suggesting links beween UV and ozone in stratosphere modulating the NAO.

‘Definitive identification of these `top-down’ solar influences on the troposphere is difficult; however, models show that the stratosphere has the potential to play a crucial role in regional climates. For example, Scaife et al [18] have demonstrated that stratospheric trends over recent decades, along with downward links to the surface, are indeed strong enough to explain much of the prominent trend in the North Atlantic Oscillation (NAO) between the 1960s and the 1990s, with implications for regional climate in Europe, particularly in winter. Effects have also been identified in the southern hemisphere [19]. Lockwood et al (2010)

UV varies much more than TSI. There was a 1000 year high around 1985 – and currently activity is at 90 years lows and most probably heading down.

With so many experts here it should be quite easy answer this question: Given the amount of ice there currently exists at the poles is controversial, what is the proper amount of ice that should be there, how do you know this, and why do you think yours is the correct volume?

The warm times, when the Arctic is thawed, are when it snows and rebuilds the glaciers. We need these warm times. They are part of the stable cycle. It gets warm and snows more, then it gets cool and it snows less. Back and forth, up and down, in a very stable cycle. The temperature of earth is regulated by ice and water. Albedo goes up when it snows more and down when it snows less. If a trace of CO2 actually makes us a trace warmer, that makes it snow a trace more and cool a trace more and it does not matter.

It is rather a complex and dynamic, non-linear problem – as opposed to gravity. As well it is a multi-dimensional problem involving population, development, energy, environment and economics.

As Voltaire said, ‘uncertainty is an uncomfortable position – but certainty is an absurd one’. Uncertainty leaves open possibilities for making new connections – it is the dynamic in which science is created and the future invented.

It is rather a complex and dynamic, non-linear problem – as opposed to gravity. As well it is a multi-dimensional problem involving population, development, energy, environment and economics.

As Voltaire said, ‘uncertainty is an uncomfortable position – but certainty is an absurd one’. Uncertainty leaves open possibilities for making new connections – it is the dynamic in which science is created and the future invented.

Re. ice extent and “We shall see how this all plays out”
In reality, we can already see that the downward trend in summer extent has been recorded by satellite data and other observation, along with the shorter-term and decadal/regional variations. Arctic sea ice extent declined at a rapid pace through the first half of July and is tracking below the year 2007 which saw a record minimum September extent and the longterm trend in September sea ice extent is steady decline. The last two weeks of July were improved – but this does not mean that the Arctic is recovering. The longterm trend clearly shows decline.

There is a real possibility of an almost ice free Arctic ocean in summer in the not so distant future (Wang, 2009, Boe 2009, Zhang 2010).

ESA’s CryoSat mission is an exciting source of new data regarding ice and oceans but satellites have already revealed that the extent of sea ice is seriously diminishing. While CryoSat will help make a more complete picture, we already have a lot of evidence: submarine sonar based data from 1958 onwards, covering more than 38% of the Arctic Ocean and showing that overall ice thickness is pretty much half of what it was 30 years ago and that this thinning trend is accelerating (Kwok and Rothrock 2009); observations over the whole Arctic region from before 2007 shows that reduced ice extent was accompanied by a significant reduction in older sea ice (Rigor 2004); a corresponding reduction in overall ice thickness (Lindsay 2009, Wang 2010, Shirasawa 2009); a thinning trend measured by satellite radar altimetry (Giles 2008) and by ICESat satellite laser altimetry (Kwok 2009) showing a continuing problem through 2008 and 2009 despite the increase in minimum ice extent. The loss of older ice has also continued through 2009 (Nghiem 2010). The older ice around the North pole towards Siberia has diminished rapidly in the past decade with losses also in the Canadian Arctic Archipelago (Agnew 2010, Haas 2010).

The idea that any of this will change with a cold snap is preposterous.

Re. permafrost and “given the assumptions in the paper apparent from the abstract, I don’t see anything here to justify Romm’s alarm”

“By 2200, we predict a 29–59% decrease in permafrost area and a 53–97 cm increase in active layer thickness. By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 ± 64 Gt C. This estimate may be low..”

Permafrost covers 25 percent of the ground in the Northern Hemisphere and contains twice the carbon currently in the atmosphere. Schaefer et al use a computer model that combines temperature trends and other data to produce an estimate of the amount and timing of (irreversible thaw) and significant additional atmospheric warming. Do you understand from the above abstract what is estimated to disappear?

Anyone who understands it is rightly alarmed.

What exactly don’t you like about the scientific assumptions, Judith? The model and analysis makes a series of assumptions, and I am curious why you think the assumptions do not support the conclusion – which quite apart from the existence or opinion of Joe Romm suggests approaching danger that justifies alarm.

Try to get off Romm and other people for a change, and instead, show that you are making competent statements.

Overall, our study showed that, independent of soil type, permafrost carbon in a relatively aerobic upland ecosystems may have a greater effect on climate as compared to a similar amount of permafrost carbon thawing in an anaerobic environment, despite the release of CH4 that occurs in anaerobic conditions.

Anyone have a sense of what that means for overall release from thawing Arctic permafrost?

These records show that when Earth Oceans warm, Arctic Sea Ice Melts. When Earth gets cool, Arctic Sea Water Freezes. Warm causes cooler and cool causes warmer. This is because it snows more when the water is exposed and it snows less when the water is frozen. This is the thermostat of Earth. The Ice Core data shows that this current warm, ten thousand year, cycle is more stable now than the warm cycles between the major ice ages. Those did not hold within plus or minus 2 degrees for ten thousand years like is happening now. The ocean level is different and the cycle is more stable. Compare the Ice Core Data for all the warm periods in the past half million years.

The release of huge amounts of trapped water from melted ice changed the ocean level and caused the Younger Dyras cooling and made the system more stable. This release of water did not happen during the previous warm periods and the oceans were lowered more, enough to cut off the ocean flow into the Arctic. That can’t happen now.

“Combing through almost 500 trillion proton-antiproton collisions produced by Fermilab’s Tevatron particle collider, the CDF collaboration isolated 25 examples in which the particles emerging from a collision revealed the distinctive signature of the neutral Xi-sub-b. The analysis established the discovery at a level of 7 sigma. Scientists consider 5 sigma the threshold for discoveries.”

I would be interested to hear a statistician discuss the significance of any of this about sea ice. I don’t think we have reache deven 5 sigma with any of this. It is quite literally “a tempest in a teacup.”

On the thawing permafrost being a source of CO2 of methane. Most (Or is it all?) of the permafrost area is covered with *living* peat bogs. Sphagnum mosses need a lot of CO2 to grow and live in symbiosis with bacteria that actually break methane into CO2 which is digested by them.

“BOULDER—Although Arctic sea ice appears fated to melt away as the climate continues to warm, the ice may temporarily stabilize or somewhat expand at times over the next few decades, new research indicates.

The computer modeling study, by scientists at the National Center for Atmospheric Research, reinforces previous findings by other research teams that the level of Arctic sea ice loss observed in recent decades cannot be explained by natural causes alone, and that the ice will eventually disappear during summer if climate change continues.

But in an unexpected new result, the NCAR research team found that Arctic ice under current climate conditions is as likely to expand as it is to contract for periods of up to about a decade.”

Looks like a nice study, not sure why they are surprised by the result (I’m not).